When the coal mine auxiliary transport monorail crane equipment runs at the vertical bend in the underground roadway,the suspension connection of the monorail bearing track or the web position of the track will bend and even break.The three-dimensional model of monorail equipment,track and suspension is established using SolidWorks.The angle α between the two continuous I140E tracks used by monorail and the angle β between the connecting rod and track of the last bearing car of the lifting beam and the first driving part below the monorail heavy load during vertical turning are taken as the variables.With the maximum stress and maximum strain of the track under impact as constraints,the driving and track of the monorail crane are analyzed,and the cause of track failure is found by combining the failure location of the track.The DC280/160Y explosion-proof diesel 10-drive monorail crane of Shijiazhuang Coal Mine Machinery Co.,Ltd.is selected.Through analysis,calculation,modeling and simulation,the optimization scheme of auxiliary transportation continuous operation is proposed.Combined with engineering verification,the reliability of the scheme is proved,which provides experience for the efficient and safe continuous operation of auxiliary transportation equipment in coal mine.
以某企业生产的T-500B高速钻铣加工中心为研究对象,利用有限元仿真软件对机床实际工况下丝杆进给系统的热特性进行模拟分析,寻找出进给系统与结构铸件间的整体热变形规律,同时还根据丝杆的热变形规律,分别通过考虑结构铸件变形与否这两种不同情况,建立起机床进给系统相应的热误差模型并进行模拟验证分析,最终得出了两种情况下丝杆在有效行程范围内的热误差曲线,提高了热误差模型的准确性,对机床热误差预测模型的构建具有一定的参考价值.
Soft pneumatic actuators are often used as soft grippers, but when grasping objects with large mass, they often deform due to reaction forces, resulting in grasping failure. Aiming at this phenomenon, this paper presents a vision-based deformation observation method for soft pneumatic actuators. Taking camera records the bending deformation pictures of the soft pneumatic actuator under different air pressures, and the deformation curve of the actuator is extracted by visual processing method in order to observe the deformation of the driver more accurately. The finite element simulation software ABAQUS is used to simulate and analyze the deformation of the actuator under different air pressures and extract the deformation curve. By comparing the similarity between the experimental curve and the simulation curve, the results show that the method of extracting the driver deformation curve based on vision can more accurately observe the deformation of the driver.
The feeding selector is the key equipment in the feeding system.This paper carries out research on the current situation of the feeding selector at home and abroad,analyzes a variety of feeding selector structures and the key design points.A feeding selector structure is designed according to the requirements of a project,the controlling process is designed.The stability of the equipment is verified through tests.Considering the needs of the users and in view of the industry development trend,the optimization direction of the equipment is proposed and the relevant resolution which provides reference and guidance for the design of other feeding selector is given.
In order to realize the functions of rapid Autonomous Simultaneous Localization and Mapping(SLAM),accurate path planning and obstacle avoidance of mobile robots in unknown environments,this paper uses Jetson nano as the main control,SMT32 as the lower computer,and uses the depth camera RGB-D,inertial navigation sensor IMU,laser radar and other sensors to build the hardware system of the autonomous mobile robots.The control system is based on ROS system,and a"RGB-D+IMU+lidar"multi-sensor fusion SLAM strategy is proposed,and the ORB-SLAM3 algorithm is used to realize fast real-time Simultaneous Localization and Mapping(SLAM).Dijkstra algorithm is used as the global route planning algorithm,and DWA algorithm is used as the local route planning algorithm to realize path planning and obstacle avoidance.Finally,the experiment is carried out in the real environment,and the results show that the expected effect is achieved.
Drill pipe jig is a key core part of hydraulic taphole drill imported from Germany,which is used to fix the drill pipe.The drill pipe clamp adopts thread connection,because the connection can only be connected and adjusted in one direction,so the drill pipe cannot rotate in the opposite direction.In addition,due to the damage of the thread surface,the oxide layer will produce further damage,this oxide layer also makes the biting phenomenon of the threaded connection occur frequently,which makes it impossible to replace the drill pipe and the blast furnace is forced to shut down.In order to solve this problem,the drill pipe is changed into a groove,and the square pin is fixed with the drill pipe clamp through the groove,which limits the axial movement and radial run-out of the drill pipe and ensures the steady rotation of the drill pipe and is easy to disassemble,the positive and negative rotation is realized.At the same time,using special alloy structural steel,skillfully designed processing procedures,the drill pipe fixture can fully meet working conditions and performance requirements of the imported hydraulic taphole drill machine.
Horizontal turn milling compound machining center is common equipment in modern machinery manufacturing.As an important part,the static stiffness of sliding saddle has a great impact on the accuracy of the whole machine.In the design process of horizontal turn milling compound machining center,this paper uses SolidWorks software to establish the three-dimensional model of the sliding saddle part,and carries out static analysis and structural optimization on the sliding saddle model to obtain the best design scheme,so as to provide necessary technical support for the design of the whole machine of horizontal turn milling compound machining center.
In order to ensure the braking performance of the hydraulic disc brake of the motorcycle,this paper analyzes the structure and related parameters of a certain type of motorcycle and establishes a calculation model.By calculating the braking operation of the motorcycle under conventional braking and full load extreme working conditions,other technical parameters required for the motorcycle are determined,and they are checked according to the GB 7258-2017 national standard(technical conditions for motor vehicle operation safety),so as to provide a calculation basis for the development of other motorcycle types of brakes.
The electronic control system of oil drilling rig in China is about to be retired in a large area.Measures should be taken to restore performance and upgrade products at a lower cost.Firstly,the composition characteristics of electronic control system are analyzed,and then the characteristics and application scope of remanufacturing recovery and remanufacturing upgrade technology are analyzed.Then,the remanufacturing performance optimization method of retired electronic control system is studied from the aspects of performance improvement,environmental friendliness,safety,integration and related interface requirements.Taking the electronic control of a foreign project as an example,the overall performance of the remanufactured system is recognized by foreign users using the method studied in this paper.The remanufacturing performance optimization method can ensure the efficient recycling of electronic control system,and provide a reference direction for the transformation and upgrading of related industries in the future.
Quadruped robots have the characteristics of flexibility and mobility,great advantages in crossing terrain obstacles,and are widely used in field environment operations and play an important role.Simulation based on quadruped robots involves various aspects such as robot design,force and motion,and control methods,which is of innovative significance and practical value.This paper comprehensively uses three-dimensional modeling and Tort-based gait simulation to simulate the quadruped robot.Through the analysis of the simulation results,the changes of displacement,velocity,acceleration,joint angular velocity,angular acceleration,joint torque,ground force,etc.of the quadruped robot in the diagonal running state are obtained.
Aiming at the influence of drilling tool motion parameters on drill force and ice sampling quantity during ice sampling in lunar polar region,this paper carries out discrete element simulation analysis,designs a drilling tool using SolidWorks 3D modeling software,and establishes a discrete element model of ice in the discrete element simulation software EDEM.The designed drilling tool is imported into the discrete element simulation software for discrete element simulation analysis.The rotation speed of the drilling tool is selected as the motion parameter of the drill for comparative analysis.The simulation results show that with the increase of drilling speed,the ice sampling quantity increases gradually.The torque applied to the drill is gradually reduced.
In view of the complexity of power scene,robot autonomous operation has certain risks.If the robot motion control is wrong,it will bring unpredictable damage and impact,so before the robot faces the actual task,it is very necessary to verify the job task and functional algorithm through simulation,and monitor the robot status and interactive data with the environment in real time during the operation process to ensure that the robot completes the job task safely and reliably.Therefore,this paper proposes a kind of electric robot operation control system based on digital twin and the application of distribution network live operation.The digital twin system is constructed from the aspects of operation environment modeling,robot modeling,kinematic analysis,path planning,collision detection and so on.In addition,an experimental platform for the wire stripping task of the distribution network live working robot is built for the online monitoring experiment verification of the operation simulation.The experimental results show that the proposed system can effectively realize the distribution network operation simulation and online monitoring of electric robot.
Under the same nominal diameter,different eccentricity,different torque and fit,finite element analysis method is used to analyze the distribution and change rule of contact stress of three-arc and four-arc isometric profile coupling.The simulation results show that the contact stress of the three-arc and four-arc isometric profiles is distributed periodically along the profile curve with the same number of cycles and arcs.With the increase of eccentricity,the contact area will increase and the contact stress will decrease.If the requirements are met,the eccentricity should be increased as much as possible.The contact stress increases with the increase of torque.The connection mode of small clearance and transition fit should be adopted when transmitting small torque,and the connection mode of interference and transition fit should be adopted when transmitting large torque.When the nominal diameter is the same,the bearing capacity of three-arc isometric profile connection is better than that of four-arc isometric profile connection.
Press-ejection module is one of the core modules of the gas combination stove.In terms of action,it is necessary to realize the retractability of the telescopic knob and the flipping action of the recipe flipping component.In terms of function,it is necessary to realize manual and automatic cooking of gas combination stoves and ovens.The appearance should ensure the user's interactive experience.This paper designs a set of press-ejection module structure,analyzes its function and working principle,designs and calculates its core mechanism to ensure the appearance and function of the combined stove.
In view of the low efficiency and high defective rate of manually assembling the square seal of the caliper,an automatic assembly device of the square seal of the caliper is designed,which is composed of the loading mechanism,the assembly mechanism,the frame and the control system.It can realize automatic loading and automatic assembly.It can save manpower and improve the operation efficiency and the assembly qualification rate.Debugging and operation prove that the designed automatic assembly device fully meets the needs of enterprises.Meanwhile,it also provides a new idea for the automatic assembly of other types of seals.
In order to improve the accuracy of CNC machine tools,a thermal error compensation method for CNC machine tools is designed based on simulated annealing algorithm.This paper establishes the change matrix of the internal parts of the machine tool when they move in the direction of X axis,Y axis and Z axis for translation and rotation respectively,calculates the heat of the motor and bearing,and then adds them together to get the heat of the machine tool under high-speed movement.Based on the simulated annealing algorithm,the thermal error offset compensation model is established to obtain the state parameters of the system temperature,the transfer function of the summation unit after the temperature drops,and the positions of the X axis,Y axis and Z axis in the offset compensation model after multiple iterations.The thermal error compensation algorithm of NC machine tool is designed,and the thermal error compensation result of NC machine tool is obtained.The experimental results show that the thermal error difference of the NC machine tool on the Y axis is small,but the thermal error on the X axis and Y axis is large.After error compensation,the thermal error is reduced to 1～2 mm and 0～1 mm respectively,which shows that the thermal error compensation method has a good effect.
In order to reduce the mass of the palletizing robot's forearm,improve its dynamic performance and reduce energy consumption,based on finite element static analysis and modal analysis,the minimum mass is used as the optimization goal,the structural parameters are used as design variables,and the first-order natural frequency does not decrease,the maximum displacement and the maximum equivalent force allowable value are used as constraints,and the proxy model of objective function and constraint function is established by experimental design and response surface method.Through the optimization solution,the optimization model of the forearm is obtained.Through comparative analysis,the mass of the forearm is reduced by 41.89%under the condition that the natural frequency,structural stiffness and strength are within the allowable range.The optimization design method proposed in this paper has obvious effects.
In view of the in-flight shutdown of a certain type of helicopter,the engine on-site inspection and return inspection are carried out.The fault department is determined and the fault review is carried out.Taking the helicopter in-flight shutdown as the top event,the fault tree is established according to each engine subsystem.The bottom events are analyzed according to the outfield feedback,engine parameters,engine and fuel regulator return inspection.The failure mechanism is analyzed based on the bottom events and the failure analysis results of the fault parts,which has certain reference significance for the troubleshooting of the same type of special situation.
The landing gear compartment door lock is used to shut down and open the landing gear hatch.In the process of use,the seal ring and the fluorine plastic ring occurs shear damage.By analysis,the immediate cause of the fault is the shell manufacturing defect,which causes the seal ring and the fluorine plastic ring enter the oil groove,shear occurs when the motion is reversed.The indirect cause is failure to identify damage of the seal ring and the fluorine plastic ring during the repairing.The risk of manufacturing deviation of the oil groove of the shell is not considered and preventive measures are formulated.In the subsequent repair,we add the surface quality inspection of the sealing ring and fluoroplastic ring on the piston rod and check whether there is a significant deviation in the position of the oil groove of the shell,and perform a running-in test on the actuator cylinder.
According to the mechanical characteristics of cutter-head's connector on the shield machine,this paper carries out the force analysis of studs and positioning pins of four legs cutter-head,and the result shows that the safety factor of torque transmission is 2.81.According to the relative position relationship of the bolt hole between the newly manufactured six legs cutter-head's flange and the flange of main drive,the strength of the six legs cutter-head'connector is calculated,the analysis shows that the safety factor of the six legs cutter-head'torque transmission is 2.27,which is 19.2%lower than that of the original four legs cutter-head.Based on the above analysis results,the position of cutter-head's connector needs to be optimized.After optimization,the safety factor of the six legs cutter-head'torque transmission is 3.81,which is 35.6%lower than that of the original four legs cutter-head,and the optimized safety factor increases 67.8%than unoptimized safety factor.The strength of the cutter-head's connector meets the application requirements after optimization.
